Recent research in preservice and inservice teacher education has led to four generalizations concerning effective staff development: (1) teachers should be actively engaged in their own learning; (2) collaboration based upon mutual trust and respect between institutions of higher education, school districts, and the community is essential; (3) changes in attitudes, beliefs, and values are prerequisites for changes in curricula, teaching, and learning; and (4) change does not necessarily mean innovation. Interest in how adults learn has also grown in recent years, and theories related to age, cognition, concept development, personality, and attitude are being reexamined as they pertain to the professional development of teachers. Three types of staff development programs seem to rely on these theories. Teacher centered programs give teachers considerable freedom of choice and responsibility for their own growth within a given structure; teacher directed programs depend heavily on the expertise of practising teachers and allow teachers to play a major role in staff development; and cooperative programs balance the immediate concerns of teachers against the broad vision of institutions such as universities. The successes of these theories and programs raise still further questions that must be answered by reliable research. (JL)